Charge, spin polarization and spin transport in carbon nanotube with zigzag edges vacancies

Abstract

Graphene is two dimensional monolayer of carbon atoms with honeycomb lattice structure, the unique structure of graphene is the consequence of sp bonding.The band structure of graphene has 2 valleys associated with 2 special point s at the corner of Brillouin zone and the behavior like ``Dirac massless particle`` of energy dispersion spectra are the most interesting properties of graphene that attract the attitude of science society. Last two decades, many experimental and theoretical researches had been conducted to discover the unique electronic properties of graphene, it became the ``hot`` material for nano-electronic. Recently, in the celebrated paper of professor Son, graphene again promised to be the new material for spintronic, even the candidate to replace silicon in computer industry. The interesting aspects spin transport properties of graphene ribbons have been investigated theoretically and experimentally. It was realized that the edge structure of graphene nano ribbon play the crucial role in spin transport, the magnetic impurities also make crucial contributions. The interesting phase transition of edge state,has been discovered lately, plays an important role as well. Almost the previous researches in spin transport of graphene concentrated in zigzag edge nano ribbons with apply electric field, magnetic field and vacancies. In this research, we will investigate the spintronic of carbon nanotube with single zigzag edge vacancy area. We also consider the effect of electric field and magnetic impurities on the system. We perform numerical calculations base on the non equilibrium green function (NEG) method and mean field approximation (MFA) in tight binding system, we will investigate the spin transport dependences of carbon nanotube on intensity as well as angle of applied electric field. The results show that we can control the spin transport of nano tube by changing applied electric field.